Hi Dave and Welcome. My Name is ***** ***** I look forward to assisting you today with your question.
I want you to completely uninstall iTunes and all its components and then reinstall them. Press Windows and R keys and this will bring Run. Type control panel and press enter.
Click Programs and Features (or Uninstall a Program) in Control Panel. The remove the software in exact order (ignore if you can't find some of them).
After that, download and reinstall latest iTunes from here --> http://www.apple.com/itunes/download/
Open iTunes and play some musics. Then close iTunes. Open Link and does it recognize the iTunes Library now ?
Please let me know if that didn't work, so we can continue troubleshooting.
If you want, I can remotely connect to your computer and try to fix the issue myself for you while you watch. This is an optional additional service.
That will also work Dave. If Link is not updated to work with latest iTunes, then it would cause this issue. Remember, after installing newest version you may need to downgrade the library file. Other wise you may get a error when you open iTunes like this library is created on new version and like so. I will send you instructions to do that. It is pretty simple.
You can find different versions of iTunes from here --> https://support.apple.com/en_US/downloads/itunes
Better to use the same version of iTunes as other PC since you confirmed that is working.
You can also reinstall Link after installing iTunes if needed. Let me know how it goes